Xylitol

Xylitol is a sugar alcohol, one of a group of sweeteners that the U.S. Food and Drug Administration permits as sugar substitutes. The FDA explains that sugar alcohols range from about 25% to 100% as sweet as sugar, are slightly lower in calories, and do not promote tooth decay or cause a sudden rise in blood glucose.

In chemistry terms it is made from xylose by reducing its carbonyl group, which is what turns a sugar into an alcohol form. Because sugar alcohols are not fully digested, eating large amounts can cause bloating, gas and diarrhea, according to Penn State Extension.

Polyols also add bulk and a slightly cool taste, help foods retain moisture, and do not lose sweetness when heated, according to university extension and FDA guidance, which is why sugar alcohols turn up in sugar-free baked goods and candies. They do not brown the way sugar does, so baked goods can look paler. Check labels, since blends can change how much replaces sugar.